The Use of a Mineralized Allograft for Sinus Augmentation: An Interim Histological Case Report from a Prospective Clinical Study Abstract: A prospective clinical research study of various graft materials lined for the augmentation of huirum maxillary sinuses is currently in progress at New York University Department of Implant Dentistry. This interim case report describes the healing response after a sinus augmentation procedure using a new mineralized CttnceUottS bone allograft. The results after 9 jiumth.s of healing demonstrated a vital bone content of 25.2% in the grafted sinus, as ascertained from a trephine core taken from the superior aspect of the lateral window area. Although the vital bone requirement for implant survival in an augmented sinus is unknown, the 25.2% vital bone demonstrated" in this case compares favorubly with that reported in the literature for other augmentation materials, including xenografts, alloplasts, and autogenous bone. Augmentation of the maxillary sinus has heen shown to be a predictable method ot increasing posterior maxillary bone height, making it possible to place dental implants when the residual alveolar ridge is deficient in bone volume. The original protocol for this procedure used only autogenous bone from intraoral or extraoral sources.1 ° Using autogenous bone required a second surgical site, increased the length of the surgical intervention, increased the surgical risk, and increased postsurgical morbidity by exposing multiple sites. Bone replacement grafts are now used in sinus augmentation procedures to avoid the drawbacks inherent in the harvesting of autogenous bone. Their efficacy has been demonstrated by high implant survival rates in sinuses augmented with these materials." The graft materials for bone replacement include allografts,8 bovine-derived xenografts,"!i and alloplasts."'lh Mineralized cancellous bone allograft (MCRA) h;is been used as a grafting material in the treatment of periodontal Ixme defects, in oral surgery for extraction sites, and tor ridge augmentation or sinus augmentation before, or concurrent with, implant placement. ''IV MCBA is a human bone product obtained from cadaver sources that has been processed and sterilized. A form of this graft material, Puros,1 prepared by a new processing and sterilizing procedure, Tutoplast,b is currently being used as a bone replacement graft for sinus augmentation procedures in a prospective clinical study conducted by the NYU Department of Implant Dentistry. This processing and sterilization destroys the unwanted microbes but maintains the porous bone mineral structure as well as the natural extracellular collagen matrix proteins that are important tor cell attachment and bone remodeling. ' After a careful review of the literature it was noted that there was no histologic verification ot using this material in sinus augmentation surgery. Therefore the purpose of this interm report from the ongoing NYU study is CE2 •Ziimiu-r Dental Inc. Carlsbad, ( \ 92008 7 )08; (800) 854-7 Tutogen Medical, Inc, Alachua, 11 *2615; (386) 462-0402 Stuart J Froum, DDS Clinical Professor, Department ot Surgical Services (Periodonncs) and Ashman Department ot Implant Dentistry Dennis P Tarnow, DDS Professor and Chair, Ashman Department i>l Implant Dentistry Stephen S Wallace, DDS Associate Clinical Professor, Ashman Department of implant Dentistry Ziad Jalbout, DDS Graduate, Ashman Department of Implant Dentistry Sang Choon Cho, DDS Clinical Av.ist.ini Professor and Associate Research Scientist Ashman Department of Implant Dentistry Now York University Collect- ut [Vntisrry New York, Now York Michael D Rohrer, DDS, MS Professor and Director Division of Or;il ;iiii) Maxillofkcial Pathology and H;ird Tissue Research Laboratory University of Minnesota School of Dentistry Minneapolis, Minnesota Hari S Prasad, BS, MDT Senior Research Scientist University ot Minnesota School ot Dentistry Minneapolis, Minnesota Learning Objectives: After reading, this article, ihe leader should be able to: • Discuss the origin and use ot a new fonn of mineral' i:L'd cancellous bone allo* graft (MCBA), Puros, for sinus augmentation. • Describe the sinus lift procedure using Puros and autogenous bone. • Describe the histological response around the particles of MCBA, 9 months after gniting the sinus Puros. Vol 26. No. 4 Compendium /April 2005 CE 2 Figure 1—Preoperative panoramic radiograph. Figure 2—Periapical radiograph identifying hopeless teeth Nos 4 and 5. Figure 4—Mucoperiosteal flap elevated with window outlined Figure 3—Preoperative planning from computer axial tamographic (CAT) scan with SIM/Plant analysis. Figure 5—Oval window elevated with membrane perforation visible, Figure 6—Collagen barrier membrane placed over perforation. to histologically evaluate MCRA (Puros) in a sinus augmentation procedure after graft maturation. Clinical Report An 86-year-old woman presented to the Department oi Implant Dentistry at NYU Dental Center after a 2 year absence to continue her implant treatment. Dental diagnosis included clinical and radiographic evaluation (Figure I). Periapical, panoramic, and computer axial tomographic (CAT) scan radiographs were taken to evaluate the oral condition and develop a treatment plan. The maxillary right premolar teeth were deemed hopeless and extracted (Figure 2). Four implants at teeth Nos. II through 14 had been placed 2 years earlier and remained unloaded. The patient had 5 mm to 6 mm of crestal bone remaining below the sinus floor in the righl molar area as determined by CAT scan and SIM/PI,mt evaluation* (Figure 3). There were no medical or dental contraindications to Treatment. Before surgery she was verbally informed of the alternatives to implant treatment and told of the benefits and risks of each treatment option. She wanted to avoid a removable prosthesis and agreed to a treatment plan that included sinus augmentation and implant placement to replace teeth Nos. 3 through 5. The patient consented to being included in NYU's M.IU™1M NV, tJIVn Hurrm-. M D J I * ! ; 11411 557-0121 Compendium / April 2005 Vol. 26. No, 4 CE2 \ Figure 7—Collagen barrier membrane placed over lateral window. Figure 8—Primary llap closure. Figure 9—Re-entry at 9 months snows dense graft resistant to probing. Figure 10—Site of trephine core is in distal, superior location in sinus. mmm® 7T?' >x-v .v.\v Figure 11 A—Three millimeter diameter core clinical and histoloyic.il study comparing graft materials used for sinus augmentation, and signed a consent form approved by the Institutional Board or Research Associates (IRRA), NYU School of Medicine. The patient received 500 mg Augmentind 1 hour before surgery. The following surgical steps were then performed: administration of local infiltration anesthesia (lidocaine with epinephrine 1:100,000), a crestal incision from tooth No. 1 to tooth No. 6, reflection of a full thickness mucoperiosteal flap exposing the lateral wall of the sinus, and preparation of an oval window in the lateral sinus wall (Figure 4). The bony window was then elevated together with the sinus membrane (Figure 5). After ele- • • Figure 11B—Three millimeter diameter core. vation, a small perforation of the Schneiderian membrane was observed and subsequently covered with a resorbable collagen membrane1' (Figure 6). Autogenous bone harvested from the tuberosity and window was added to the Puros graft. The graft mixture, consisting of 10% autogenous bone and 90% Puros, was hydrated in sterile saline and placed in the newly formed subantral compartment. The MCRA mixture consisted of 50% (3 mL) of .25 mm to 1 mm particle size and 50% (3 mL) o\ 1 mm to 2 mm particle size. More resorbable collagen membrane was hydrated tor 1 to 5 minutes in sterile saline before placement, then contoured and placed over '(llaxoSmithKtiiw, Middlesex England UK; (020) 8990 9000 Vol. 26. No. 4 Compendium /April 2005 CE 2 Figure 12—Implants placed anterior to and into sinus graft Figure 13—Radiograph of implants in Figure 12. the prepared window.22 The membrane extended 3 mm beyond the limits of the prepared window and was placed in close apposition to the hone (Figure 7). Primary closure of the flap was achieved with interrupted 4-0 silk sutures (Figure 8). The patient was placed on antibiotic (Augmenrin 500 ing 5 times a day for 10 days after surgery), an anti-inflammatory (MeJrol Hose Pack''), and analgesics (Tylenol with Codeine ~V). Rinses with .12% chlorhexidine digluconate twice daily for 2' weeks were prescribed. Healing was within normal limits 7 days after surgery, and the sutures were removed. Nine months later, at stage I surgery, ) implants were placed and a trephine core sample (10 mm in length and 3 mm diameter) was retrieved from the lateral window area in a manner that did not compromise implant placement (Figures 9 through 1 3). This method of core retrieval is consistent with previously published NYU sinus studies.10 Both the lateral wall and implant osteotomy sites presented resistance when the drill was used. The patient was placed on antibiotics (amoxicillin 500 mg 3 times a day) for 10 days after surgery beginning 1 hour before surgery and was given a prescription for analgesics. Rinse:-* were prescribed with .12% chlorhexidine digluconate twice daily for 2 weeks. The sutures were removed 7 days after surgery. The patient was seen for follow-up at 1 week, 4 weeks, 8 weeks, and 16 weeks after implant placement surgery. All implants appeared to be healing within normal limits. Histological Report The retrieved core was sent to the Hard Tissue Research Laboratory for histological Pfeei NewYorl V1! 10017; (212) 573-2323 "Ortho-McNeil Pharmaceutical Inc. Raritan, NJ 08869; (908) 218-6000 analysis. The histologist was blinded to the nature of the bone graft material in the sample. 111 The specimen was fixed in 10% neutral buffered formalin. The specimen was then dehydrated with a graded series of alcohols tor approximately 14 days. After dehydration, the specimen was infiltrated with a light-curing embedding resin1. After approximately 14 days of infiltration with constant shaking at normal atmospheric pressure, the specimen was embedded and polymerized by 450 nm light with the temperature of the specimens never exceeding 40°C. Tlie specimen was prepared by the cutting/ grinding method of Donath and Rohrer,-;-4 and cut to a thickness of 150 mm on an EXACT1' cutting/grinding system. Then the slide was polished to a thickness ot 35 iim to 45 um on the EXACT micro grinding system, and was stained with Stevenel's blue and Van Gieson's picric fuchsin. Microphotographs were taken, scanned, digitized, and analyzed using the public domain National Institutes of Health image program (developed at the US National Institutes of Health and available on the internet at http://rsb.info.nih.gov/nih-image/). Three sections were analyzed from the core. The percentage of vital bone, connective tissue, and residual graft material was determined by an average of these 3 sections. Results The average percentage in the 9 month post sinus lift core of vital hone was 25.2%. The average percentage ol connective tissue and marrow was 58%. There remained 16.8% of residual graft material in the core. However, the MCBA graft particles were in apposition to ' 72OC VIA , 1 leracus Kulzcr, I rermany, I irun..-r Weg 11. Hanau D- 63450; 49.6181 J540 16 1 <:iki Apparatehau GmbH & Co, Nonjerstedt, (ierman} Compendium / April 2005 Vol 26 No 4 the new hone and in many cases nearly indistinguishable. Representative histologic examples :ire presented in Figures 14, I1), and 16. Discussion To the authors' knowledge, this is the tirsr human case report to histomorphometrically evaluate vital bone production in the maxillary sinus using Puros hone replacement graft. The analysis wa- made ^ months after grafting of the maxillary sinus. The cadaver hone processed into Puros is obtained from a certified (American Association of Tissue Banks) tisMie hank. Honor material is deemed suitable based on medical, social, and sexual history inquiry, physical examination, autopsy finding (it performed), medical history/records review, and laboratory tests. Tissue is procured aseptically and held in approved storage until preservation and sterilization processes are performed. The allograft material consisted of human cancellous donoi bone that was treated for biological safety through a 5-step proprietary (Tutoplast) process that included delipidization (defatting), osmotic contrast treatment, oxidation with hydrogen peroxide, solvent dehydration, and limited-dose gamma irradiation (17.8 GY).25-2* This method of processing has been shown ro inactivate the HIV virus and the agent responsible for Creutzfeldt-Jakob disease.^ Reports of bovine spongitorm encephalopathv (BSE) in humans27 and the finding that viable HIV viruses have survived in allogenic hone tissue after freezing, washing, and treeze-drying28 have raised concerns about disease transmission from .venografts and alloyrarts. International standards define sterility as the absence of any viable pathogen.29 Common methods ot inactivating pathogens (bacteria, viruses, fungi, protozoa) in heterogeneous n>sues before sterilization include the application of ultraviolet light, heat, irradiation, and/or chemical energy ro change the conformation of proteins by altering chemical bonds, or to fragment the DNA/RNA strands. With changed conformation, proteins can no longer work properly. When the proteins in the capsid or envelope of viruses is changed in their conformation, viruses can no longer infect cells.1' It DNA/RNA is changed through low-dose irradiation, natural ultraviolet light, strong alkali (pH > 12) or low pH (pH <3), bacteria die or can no longer replicate. Proteinaceous infectious particles called prions have been identified as the agents that cause and transmit BSE and related encephalopathies. Prions are extremely resistant to conventional inactivation procedures, including irradiation, boiling, dry heat, and chemical treatment (formalin, betapropiolactone, alcohols).'7"'4' Denaturing organic solvents (phenol), chaotropic agents (guanidine isothiocyanate), or alkali (NaOH as used for solvent dehydration in the Tutoplast process) have been shown to effectively inactivate prions 4M7 Most tissue hank processing techniques effectively minimize the risk ot disease transmission from dangerous pathogens in their products. Screening of potential tissue donors is also imperative to rule out health and lifestyle factors that could engender susceptibility to such pathogens as the HIV viruses.28'48'49 Sterility validation studies and adherence to good manufacturing practices help to ensure product safety. Since the advent of the sinus elevation procedure, researchers have been evaluating various bone replacement grafts to determine which are best suited for the successful placement of endosseous implants. Many hone replacement grafts have been used and evaluated histologically. These include allografts,8 alloplasts,10 and xenografts.10"56'*0 The use of an ideal material should result in the formation of a high percentage of vital hone after reasonable graft maturation. The literature shows a wide range of results using these different grafting materials, with vital bone content ranging from 14% to 44%.10" Implant survival rates with mineralized xenogratts and alloplasts have been reported to be as high as or higher than those achieved with autogenous hone grafts.6'' While a significant percentage of these mineralized graft materials may not be resorhed,14'171U there is no evidence that this residual graft material adversely affects osseointegration and. ultimately, implant survival. In fact, the high implant survival rates reported with mineralized hone CE 2 Vol. 26, No. 4 Compendium/ April 2005 CE 2 replacement »raft,s may be due in pan to the increased stability (greater density) that they provide. 10. On the other hand, reports on the use of mineralized and demineralized human allografts have not been as promising.61' ' The only positive report occurred when crestal IIhone heights were greater than 4 mm.a Conclusion 12. This case describes the healing response after a sinus augmentation procedure using the mineralized cancellous bone allograft, Puros. [3, The results after 9 months of healing demonstrated a vital hone content of 25.2% in the grafted sinus, as ascertained from a trephine core taken from the superior aspect of the hit- 14. eral window area. Although the vital hone requirement tor implant survival in an mi^- ]S mented sinus is unknown, the 25.2% vital hone demonstrated in this case compares favorably with that reported in the literature for other ,(i augmentation materials including xenografts, alloplasts, and autogenous bone. The remaining Puros particles (16.8%) were in close apposition to the new bone. Il might be reasonable to assume that, over time, these particles will be absorbed and replaced by new hone, which would result in rhe formation of a greater percentage of vital hone. 1 lowever, one must mite thai more extensive research is required. References 1, [>. ivni P|. |.lines RA. (drafting of the maxillary sinus floor 20. with autogenous m.irruw 111J Nme. ./ Oral SWTJ. 1980:38:613-616. 2 Wi«\l RM, Moore PI Grafting ol tin- maxillary sinus with immorally harvested autogenous hone prior to implant place- .... tit Im (Oral MaxMofat Implants. 1988;3:2O9-214- 21- t. Keller EE, Ecki n SE, lolniiin DE Maxillary antral and nasal one-stage inlay composite kme Kraft: Preliminary report on JO recipient siies. [ ( W Ma»fcf« Surg. 1994:52:438-447- 4- Blomqvist jE, Albenus P, Isaksson S. RetrospetS ive analysis oi 22. one-stage maxillary sinus augmentation wiih eiiiiosseous implants. in(j( kdMaxMofac rmptmts. 1996;11;512-521. *>. Van Den Bergh IP, Ten Bru^enkate CM, Krekeler ti, et :il i . floor elevation and grafting with autogenous iliac ire^i bone. C tin < W [mploms fcs. I WS;^:42l>-4 55. n. 6. Wallace SS, Froura SJ. Effect of inaxillan sinus augmentation on the survival ol endosseous dental implants: A systematic review. Ann PeriodonwL 2003*328-343. 7. IVI hiM'To M. ksion T, Hraneei II l . e t al. Systematic review 24- ol survival rata for implants placed in the ^rr:ikeLl maxillary sinus, Im f PerwdtflUics RcilinatU* t\iU. In press. 8. Van I ten [VrKh JP, ten Bru^enkate t:M, Krekeler G. er al. Maxillary sinus il.«.t elevation and grafting with human Jem- 2V iiK-r,ilized tree:L dried bone. CIm Oral Implants Res. 200C;l 114^7-4^. 18 19. Valentini V, Abensur P. Maxillary tl* K *r elevation for implanl placemeiu with demineralizcJ tVcere-tlrictl K>nt' ;nnl bovine Kino (lini\.s); n clinical study of 20 patients, bit ] Periodtmacj Restor imv I km. 1997:17:232-241. [•u.tun SJ, Tlininw HP, Wallace SS, et al. Sinus tluir elevation using anorganic h>vine bone innrrix (t\ti-iit >r;it/N) with and without autogenous bone: A clinical, histologic, radiographic and histomofphometrk: analysis - P:in 2 of ;in ongoing study. JnrJ PeruKimaics Restorative Dent 1998:18:528-543. Villfntmi P, Abt-nsur D, Wen; B, e1 :il. Sinus grafting with porous bt>ne mineral (BtoOss) ti»t implarn placement: A 5- UMI MIKII. on 1^ patients. Int i Penodonoa Restomtne Dent. 2O0ft2O:245-253. Hisiiic V, l^ilint: A, BrantingC Reconstruction of severely resorbed alveolar crests with dental implants using ;i bovine hone mineral tor augmentation. \iu] Oai Maxitlofat Implarus. 2001:16:90-97. Miilhiinin M, Scnnt'iity I., ijnul^run S. A clinical and histolo^ ic evaluation ot iiupl.iii: inro^T.tlion in ilu |\isu-iiot maxilla .ttrur sinus floor augmentation with autogenous K.ni-, bovine hytiroxyapatite, or a 20:80 mixture, /NI ./ [ htd MaxiKofac Imffanx. 2002:17:635-643. \ ' . l U - i n n i l I1, A l v i w i i f [ t | - M ; i \ i l l , i n s i n u s aiiiliniL! wiirh . m o r - ganic bovine bone: A clinical report o( long-rerai results. IntJ Oral MaxNafac Implants. 2O03;18:556-56O. llodriguez A, Anasrassov GE, Lee H, et a!. M;ixili;iry sinus augmentation with deprotetnated bovine bone ,inj platelet riili ]ii;isin;i with simultaneous insertion oi endosseous OroJMawflc^kSKjg. 2003^1:157-163. JK. A ^'2 vv;ir clinical evaluation ot reswhable hydroxylapatite OsteoGen* I HA Resorb™) used for sinus lift augmentations in conjunction with the- insertion o1 endosseous implants. J 1 hal ftnpbiail. 1991;17:152-164. DeLeonardis D, Pecur.i GE. •\iu:nietit;stion ot the maxillitry sinijh with calcium sulfate: one-year clinical re|N>ri from n prospective longitudinal study. Jut J ( Va/ Maxilkxfac implants. 1999:14:869-878. Wheeler SL. Sinus augmentation h'r dental implants: the u-i oi alloplastic materials. .1 Oral Maxillofac Surg. 1997:55:1287-1293. Becker W, Urist M. Becker BH, el al. t linical and hi^ologic observations of sites implanted .uili intraoral autologous kwle unitts or allografts. 15 human ^ist1 reports. / Periodontol- 1996^7:1025-1033. Feuille F, Kitipp Cl, Brunsvold MA, el al. Clinical and histologic evaluation of bone replacement grafts in the ireiitmt'nt of localized alveolar ridge lefects. Pan I: Mineralized freeze- Llrieil bone allograft. ftu J Periotlonrics Restorative Dent, 2003:23:29- S5. • I in m l Estimate of ihi- theoretical nsl; of transmission d i. 'reutzfeldt-Jakob disease by human dur,i mater grafts manufactured by the Tutoplasi process. A commissioned rej»<r( for Biodjnamics (nttnialiond ltR>5. Tunow l^l1, W.illutt" SS, Friiuni ^1, et ;il. Histologk iintl clui' ical comparison ot bilateral sinus tlimr elevations with and without Kimer membrane placement in 12 patients: Part 1 ot .in ongoing prospective study. Fru ./ Pertxbnna Restoraoi* D<™. 2O0O;20:llf>-125. IX.n.uh K, Brenner 11. A method lor the study of undecalc fied bones and teeth with the attached sutt tissues: the Snpp Sihlirf (sawing and grinding) technique. ./ (Vni Pathtil. l982;llJ18-326. Ruhror MIX Schubert C C The cutting-grinding technicjue for histologtcal preparation .1 lindccalcified botw and boneanchored implants: improvements in instrumentation and procedures.* kd SurgOralUedOrd i'aihl ltW2;74:71-7H. T;klic D, Epple M. A thorough physicochemical characterization 01 14 calcium phosphate-hased bone substitution materials in comparison to natural IT me. Binmai&iak. 20O4;~;):L'^T 994. Compendium I April 2005 Vol. 26. No. 4 26. -7- 2fl JO. !2. i J. J4. Gunter KP. Scharf H-P, Peach II-J, eT aL Ostecrintegratton of solvent preserved bone transplants in the animal model. Osteofagie. 1995:5:4-12. Sojyl A, Tote AJ. Risk assessment ol bovine spongiform encephalopathy transmission through bone graft material d e r i v e d from h o v i n c N i n e HM\I loi J i i i i . i l i | p l k a i i o n s . J Paiadomat 1999:70:1053-1063. M.srthy S, Richrer M. Human immunodeficieix \ \ iius a u n - in in rib allogtaftsj Oral UaxHofix Surg. 1998:56:474-476. American National Standard: Sterilization ot health care products- Requirements tor validation and routine control - Radiation sterilization WIS/AMM//ISO 11137-1994. Arlington, VA: Association lor the Advancement ol Medical Instrumentation, 1995. Lwofl A, Anderson Tp [acob E Rom.irks on the characteristics t>t the infectious viral particle. Aim Insl Pasteur (Cans). 1959#7:2ol-289. Brown P, Liberski PP, Wolff A, t-t al. Resistance of scrapie infectivity (o steam autoclaving after formaldehyde fixation and limited survival atter ashing ai S60 degrees C: practical and theoretical implications. J Infect Dis. I * V ; I ri 1:467-472. Taylor DM. \ k t onnell I, Fermie K. The effect >>t dry heai on the ME7 strain o) mouse-passage scrapie agent../ Gen Virol. 1996:77:3161-3164. Bolton IX". McKinley PM. PrusinerSB. Identification d a protein that purifies with the scrapie priori. Science. H.s;;:i,s: | H1') I \\ I Bolton DC, McKinlei I'M. PrusinerSB. Molecularcharacteristics ot the major scrapie priori protein. Science. 1984;Z3:5898 590 • Gabiion R, Pnisinei SK Priori liposomes. Biochem j . 1990:266:1-14. S.it.ir I. Ceroni M. Piccaido P, el al. Suhcellular distribution and phystochemicai properties ol scrapie associated precursor protein and relationship with scrapie ayent. Neuroiggy. '7. Bellinger-Kawahata C, Diener TO, McKinley Ml1, ei al Purified scrapie ions U-.M tnactivation by procedures that hydrolyze, modify of shear niicleic acids. Virology. 1987:160:271-274. Jo. Aiper T, Cramp WA, i laig DA, et al. Does the agenl tor scrapie replicate without nucleic acid? Nature. 1967:214:764-766. S9. Bellinjjer-Kawahara ('., (. leaver JE, Diener TO, a aL Purified scrapie ions resists inactivation by UV irradiation. ] Virol. 1987:61:159-166. 40. McKinley MP. Masian FK. Isaacs ST. el aL Resistance ot the MTiii'li' ageru w inactivation by psoralens. P/iiiicdiiii Phowbtot 1983^7:539-545. 41 PrusinerSB. Novel prott in K icenuN infectious part it!t^ t;mse sctapie. Saence. 1982:216:1 'd-144. 42. Brown P, Wolff A, (_;:ijdiLsek DC. A simple and effective method tor inactivating virus infectivity in tonmlin-fixed samples Irom patienrs with (..%reut:teIJt-J:ikoh disease. Naaobg}. 1990-.40587-890. 41. Prusinei SB, Groth DF, McKinley MP, et al. Thiocyanate and hydroxyl ions inactivate the scrapie agent. Proc Nad AccuiSa ( XV !^S1;78:4606-4610. 44. Pnwiner SB, McKinley MP, Bolton DC et al. Priorw methods tor n^sav, purification ;inil characterization. In: Maramorosch K. Kowprowski II, eds. Methods in Virology. New York: Academi< Press: 1984:293-345. 45. Prusinei SB, tiroih HF. Serban A, i-t aL Attempts to restore scrapie priori infectivity after exposure to protein denaturams. Pr« Nad Acad Sd 1 SA. 1993:90:2793-2797. 46. Taylor DM, WixiJ^itt1 SL. Atkinson MJ. Inactivation of the bovine spongiform encephalopathy agenl by rendering procedures. Vet Rec. 1995:137:605-610. of bioac tiv genous hone for si i uis floo 47. Taylor DM, Woodgate SL, Fleetwood AJ, et al. Effect of rendering procedures on the scrapie agent. VW Rec. 1997:141:643-649. 48. Buck BE, Rcsnick L, Shah SM. ct al. I luiiian immunodeticiency virus cultured from hone. Implications tor transplantation, d m Ortfcop. 1990:251:249-251. 41'. Simonds Rl, I l o l m k - r c SO, llurwit: RL, et al. Transmission of human immunodeficiency virus type I from a seronegative organ and rtssui donor. \ iingf J \{cd. 1992:326:726-732. 50. Siniler lXi, Holmes RA. Sinus litt procedure usinj; porous hydroxyapatite: A preliminary clinical report. J Oral Impknnl I987;l J:239-253. 51. Tadjoedin ES, DeLange GL, 1 lolzmann PJ.et al. Histologic observations on biopsies harvested following sinus floor elevation usmu, a hioactive ylass material ol narrow size range. (\tin ( hal Implants Res. 2000;IlJ34-344. Tadjoedin ES, DeLange CiL, Lyaruu IXM, er al. H\^\\ con- . material (BioGran* I vs. autOi li vation. Clrn < W ImjtLmts Res. 2002:13:428-436. 53. (..'ordioli G. MazzoccoC'., Schepers E, et al. Maxillary sinus floor augmentation using bioactive t;la>s granules and autogenous bone with simultaneous implant placement, ^ fin Otd Im/fciy fcs. 2001:12^70-278. 54. Ann Z, Nemcovsk\ I'l-i. Pa\an l\ Nonctramic hydroxyapatite Nine derivative in sinus augmentation procedures: ^ lintcal and histomorphonietric observatiorts in 1^ consecutive ciises. ImJ PeriodanlJcs Reuoratnx Dent 2OO.?;23:Wl-:i,sy, i i . ^:al>o (i, Suha Z, Hmhak K, er al. Autogenous bone versus bera-tricalcium phosphate graft alone tor bilateral sinus elevations (2- and }- dimensional computed ronn^raphic. histologic, and histomorphomemc evaluations): preliminary results. iniJOralMaxillnfac Implants. 2001;16:6HI-<"•>: 56. Piaitelli M, Favero A, Scarano A. el al- Bone reactions to anorganic bovine bone (Bio-Oss) used in sinus augmentation procedures A hbtologk long-term report "I 20 cases m humans. IntJOwiMaxtBafai ftnpfemts. l<W;l4:Ni5-»40. 57. Yililirim N!, Spiekcrmann H. BiesterfeW S, et al. Maxillary sinusaugiin-'ntatiixi usini; \eno<;enK Ixnn substitute material BioOss* in combination with venous blood: A histologit and histoinorpl!"iiiciric study in humans. C .'iin Orai Implanc Res. 2000;l 1:217-229. 55. Jovanovic SA, Spiekermann E, Richrer EJ, et al. Guided tissue regeneration around titanium dental implants. From: Laney WR, Tohnan OF, eds. TLSSUL- bvegraaon in Omi (Wiu/jc-JicomJ Miuilti/in-ml Reconstrucoon: Proceedings, v.'ar.•! Stream, It Quintessence; 1992^08-215. 5l). YilJinm M, Spiekermann H, Handt S, et al. M.t\illar\ sinus augmentation with the xenograft Bio-Oss and autogenous intraoral bone tor qualitative improvement of the implant site: A histologic and histomorphometnt stud} in humans. Jut J l Hul \U\illoJM Indiana. 2001; 16:2 i- ? V 60. Art:i Z, Nemcovsky C"E, Dayan IX Bovine-HA spont; iosi Wntks and immediate implant placement in sinus augmentation procedures. Histopathological and histomorphomctnc observations on different histoiogical staininHs in 10 consecutive • viiunts. I 'Urt Oral [mpfemtj Res. 2002:13:420-427. 61. Jensen OT, Shulman LB, Block MS, ei al. Report ot the Sinus Consensus Conference of 1966. Inl J Oral MoxiUo/oc Implants. 199S:13(suppl.):l 1-12- ii2- Langer B. Langer I. L^< ol allografts for sinus grafting. In: Jensen OT, ed. The Sinus Bone Graft. Chicago: Quintessence. 1999:69-78. (il. Jensen OT, Sennerhy L Histologic analysis ol clinically retrieved titanium micro implants placed in conjunction with maxillary sinus floor augmentation, hu ] Oral ic rraplaius. l W M ; n : 5 ] ? - 5 2 l . CE 2 Vol. 26, No. 4 Compendium / April 2005 Reprinted from the April 2005 issue of Compendium. © 2005 Ascend Media LLC. 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